Full wave rectifier



June 15, 1943. w. w. wA'rRous; JR 2,321,959

FULL WAVE RECTIFIER 7 Filed July 16, 1941 2 Sheets-Sheet 1 58 r I j? 57 J J9 64 56 11 5 53 n v 7471' 17W m a? 25 93 i 71 75 9 75 69 79 INVENTOR MM 11 200.5, 07?. BY MW ATTORNEY June 15, 1943. w. w. WATROUS, JR, 2,321,959 v FULL WA E RECTIFIER I Filed July 16 1941 2 Sheets-Sheet 2 INVENTOR W. Aways, .r/z'

BY MW ATTORNEY another in the presence of an ionized gas.

Patented June 15, 1943 2,321,959 FULL WAVE RECTIFIER Ward W. Watrous, Jr., Bloomfield, N. 1., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application'July 1d, 1941, Serial No. 402,573 18 Claims. (Cl. ear-27.5)

My invention relates to rectifiers, and especially to full wave gaseous rectifiers.

An object of my invention is to provide a gaseous full wave rectifier in which-the ionization is confined to each individual anode space.

Another object of my invention is to provide a rectifier structure in which the spacing of the various metallic parts adjacent to the discharge can be kept to a minimum.

Another object of the invention is to increase the cathode efficiency by completely surrounding it with anodes and to reduce end loss by having only two p ints instead of three or four points of filament support, as are in existing designs.

Another object of the invention is to reduce gas .clean-up" to a minimum.

Another object of the invention is to provide a cathode having all parts available for emission,

Another object of the invention is to provide a large area for anode heat radiation.

Another object of the invention is to prevent long path arc backs between the anode sections of a full wave rectifier.

Other objects and advantages of .the invention will-be apparent from the following description anddrawings in which:

Figure 1 is a view in front elevation, of a preferred embodiment of my invention.

Figure 2 is a cross sectional view on an enlarged scale of the electrode structure of Figure 1.

Figure 3 through 7 are cross sectional views respectively on lines IIIIII through VIIVII of ure 2.

While full waverectifiers have been built in many forms, these various forms embody one or more inherent defects which limit the scope of the .application of these full wave rectifiers. A

list of the most common defects inherent with existing types of full wave rectifiers is as follows:

The anodes have a discharge path to one The anodes are not easily accessible to emission from the .cathode, and this results in a high pick-up.

voltage and a high arc drop. The cathode has littleor no shielding and this results in low heat eiilciency. The individual anode shielding is usually tied to one leg of the cathode, and this results in unequal pickup and arc drop voltage. The discharge impinging upon the glass bulb wall results in rapid gas clean-up. Where the anodes are enclosed, the resulting high anode temperature produces a liberation of extraneous gas. Where the filament is supported at more than two points, there is a low filament efiiclency due to and loss.

.on the underside of the insulator.

My invention herein disclosed embodies a construction which overcomes the defects listed above. In its broad'aspect my invention consists of two one-half wave rectifier element in a single envelope utilizing a common cathode.

The preferred embodiment is illustrated in Figure 1, and in detail in the other figures. The rectifier comprises a glass container in, having a base I i at one end, although two or more contact bases may be used, if desired. From the base ll extend the contact pins I2 to fit into the well-known socket construction. The bulb III has a re-entrant press l3, through which extend the various leads to the electrodes. As disclosed in Figure 2, two of these standards I4 and I5 are sealed through the press for the connection to the cathode. Surrounding the upper end of these standards, are hollow tubes l6 and il, welded thereto, and passing through a lower insulator I8 to form the base for the cathode and shield construction. The upper portions of these tubes, have aslight flange l9 and 20, respectively, that is peened in depressions 2i and 22 in the insulator.

The hollow tubes l6 and I! preferably make contact with the cathode structure on the underside 23 of the insulator Hi. This contact portion is illustrated in Figures 2, 6 and 7. The cathode preferably comprises a helical heating coil 25 of tungsten, preferably coated with a suitable insulating coating such 'as alumina, extending upward through the axial active portion of the tube. This coil has a shaft 21, extending down through a central hole 28 of the base insulator iii, The contact member between the hollow rod I1 and the heater shaft 21, comprises a member having a flat portion 29 on the under side of the insulator l8, surrounding the hollow tube i'l.

The hollow tube I! has a pressed out ring 30, to make a tight contact with this flat portion 29 This flat portion 29 has two downwardly extending flanges 3|, that extend on the inner end into bow-shaped springs 32 that terminate on either side of the shaft 21 as disclosed at 33 in Figure 6. These spring members 32, are welded to the heater extension 21. The double ribbon shape ofthe connection from the hollow tube I! to the heater wire shaft at 33 permits the transfer of a high current, such as 20 amps. without undue heating of this connection.

The spring bow 32 permits the connection to bend with expansion of the filament due to the operating temperature of the filament.

The double connection of the contact springs 32 which are generally of nickel, make easier welding to the shaft 21, which is generally of tungsten. Seated on the upper part of this bottom insulator I8, is a cap 35 having a central opening 36 to prevent any contact with the heater wire 25 passing therethrough. This cap 35 is illustrated in Figure 7, has a flared out flanged portion 31 and from this flared out flange extend two fingers 38 and 39 through the insulator to the bottom portion thereof. Contact is made to these two fingers by a metal contact 40 having a flat portion 4| secured to the underside of the insulator I8 by a flared out ring 42 on the conductor tube l6. This flat portion 4| has two downwardly extending flanges 43 and 44, welded respectively to the fingers 38 and 39 of the cap 35. Resting on the flange 31 of this cap 35 is the bottom edge 50 of the cathode proper This cathode in order to provide an extensive electronemitting area, is formed with a projection in the shape of round gear teeth 52, extending the length of the cathode. The corrugations may be transverse instead of longitudinal. This surface is coated with the familiar barium, strontium and calcium oxide coating, although other types of coatings may be used.

At the upper portion of the tube, the tubular cathode at 63 is welded to an inverted cap 54, somewhat similar to the cap 35, but having opening 55, to which the upper end 56 of the helical filament 25 is welded to maintain good electrical contact. This inverted cap 54 has extensions 51, fitted into slots 58 in an insulating cap 59 at the upper portion of the tube to center the cathode structure in the tube. A cathode sleeve or shield 60 spaces the insulators I8 and 59 from each other. This shield 60 is cylindrical in shape and has its bottom edge 6| in a circular groove 62 in the bottom insulator I0. The upper edge 63 of this shield is inserted in a groove 64 in the upper insulator 59.

At the longitudinal mid-point of the cathode, is preferably welded a partition 65 to separate the space between the cathode wall 5| and the shield 60 into an upper compartment 66 and a lower compartment 61. Around the wall of the shield 60 in the upper compartment, I provide a plurality of slots 68 for the passage of electrons therethrough and I also provide in the lower compartment a plurality of openings 69 in the shield 60 for the passage of electrons therethrough. Around the central portion of the shield 60, I provide cylindrical insulators 10, and secured thereto by annular brackets H and 12 having a cylindrical portion 13 and 14, respectively welded to the outer wall of the cathode shield 60 and an outwardly extending portion or flange and 16 in contact with the flat inner portion of the wall of the insulators 10, 10. The insulators 10 and 10' may be molded in one piece but it is easier to mold the particular shapes I desire in the two pieces 10 and 10' than in one unit.

The flanges 15, 16 cover a large portion of the surface of the insulator normally exposed to the discharge and thus cut down the gas clean up by insulating surfaces exposed to ionized gas.

The insulators 10 and 10' have grooves 11 and 18 just adjacent the peripheries 19 and 80 of the supporting flanges 15 and 16 to prevent leakage by material that might be sputtered on the face of the insulator adjacent the supporting flanges 15 and 16. The outer portions of the insulators 10 and 10' are shaped to have circular depressed portions 8I about their peripheries.

An anode 82 extends from the insulator 10' and encloses the upper insulator 59 therein. This anode has its lower edge 03 peened over the edge of this depression M in the insulator 10', and also has an indentation or head 84 at the edge of the upper face 05 of this insulator 10'. The anode 82 then extends upward in a cylindrical surface to provide a discharge space enclosing the cathode and 'shield structure.

The top portion of the anode 82 is then bent inwardly at 86 to make contact with the wall of the insulator 59. An important part of my invention is the continuation of this anode into a top cap 81 enclosing the top portion of the insulator 59.

A similar anode 92 with its one end 93 peened over the edge of the depresssion 0| in the insulator 10 likewise has a depressed bead 94 binding the anode 92 at the underface 95 of this insulator assembly. The anode 92 extends downwardly to form a discharge space surrounding the slot 69 in the lower portion of the cathode sleeve 60. The bottom portion of the anode is then curved inward at 96 to make contact with the side of the bottom insulator I0. The lower anode 92 has as a continuation a second smaller cap 91 enclosing the bottom insulator I0 and having just the necessary openings therein for the passage of the tubular cathode and heater connections I6 and I1.

A contact member I00 is welded to the exterior portion of the anode 82 and has a connection III extending downward to a standard I02 extending through the press I3. The lower portion of this standard I02 may be protected by an insulating sleeve I03. Another contact member I04 is attached to the lower anode 92 and has a connection I05 sealed through the press I3 and this may be protected at its lower portion by an insulating sleeve I06.

If the cathode shield 60 is desired to be at cathode potential, this may be accomplished by having a contact member in the form of a plate IIO secured under the peened over flange l9 at the top of the tubular connection I6 and this flat portion 0 has a. finger III, extending up the side of the wall to a pinched-out opening II2, resulting in an extension I I3, on which the finger III is bent over into a flange H4 and welded thereto.

On the cylindrical side of the upper cap 81 is secured preferably four standards II5. To these standards is secured a metal member H6, having fingers II1, to bind therein a horizontal extending piece of mica H8 to make contact with the inner wall of the dome II9 of the glass container wall I20 to centralize the electrode structure therein.

Any well-known getter I2I may have its connection to one of the contact standards, such as the standard I02 connecting to the upper anode 82. Openings I22 in the upper insulator and I23 in the upper anode cap may be provided to allow excess gas pressure to be relieved from the inner portion of device but these openings will not permit any discharge therethrough.

My rectifier in its preferred embodiment disclosed on the drawing, has shields 60 and 66 which divide the tube into two separate compartments 66 and 61. The shield 60 prevents undue loss of heat from the cathode by closely surrounding the cathode structure throughoutits length. Only sufficient openings such as the foil!- illustrated in the upper portion and the tour in the lower portion are utilized for the passage of electrons.

It will be noted, however, that there is only a small amount of insulating material at either end of the region of the ionized gas. The anodes 82 and 92 substantially enclose both sections and provide additional heat shielding, but prevent any rapid gas "clean-up because the discharge is confined therein.

An important feature of the invention is the cap '1 enclosing the upper insulator and the cap 91 enclosing the lower insulator.

It the anodes were to terminate at the insulators It and 58, respectively, there is danger of an arc-back from the Junction of the metal and insulator to the other metallic portions of the rectifier. The fundamental reason for this arcback I am not prepared to assert, but believe it has something to do wtih either the field at the junction of the metal and insulation; to the varying potential of the ionized gas in combination with the equalized potential of the anode or to the charge assumed by the insulator. I do know that my experience has proven arc-backs without these caps and the absence of such arc-backs with the caps 81 and 91.

The shape of the two insulators is such asto minimize any leakage across their surfaces. The tube can be filled with gas such as argon, xenon, helium, neon and the like, or any combination of them, or with materials having suitable vapor pressure at operating temperature, such as mercathode, a ring of insulating material, surrounding a mid portion of said shield, two anodes having their edges spaced from each other on said insulating material and substantially enclosing the two ends of said cathode.

2. A full wave rectifier comprising an elongated cathode, an elongated shield enclosing said cathode, a ring of insulating material surrounding a mid portion of said shield, two anodes having their edges spaced from each other on said insulating material and substantially enclosing the two ends of said cathode, said shield having openings therethrough forming part of a discharge path from said cathode to each anode.

3. A full wave rectifier comprising an elongated cathode, an elongated shield enclosing said cathode, a ring of insulating material surrounding a mid portion of said shield, two anodes having their edges spaced from each other on said insulating material and substantially enclosing the two ends of said cathode, said shield having openings therethrough forming part of a discharge path from said cathode to each anode, and a partition between said cathode and shield separating the discharge path from said cathode to the openings in said shield for one anode from the discharge path from said cathode to the openings in said shield for the other anode.

4. A full wave rectifier comprising two spaced insulators, a cathode extending from one insulator to the other, a third insulator about the mid portion of said cathode, an anode attached to said third insulator and enclosing one of said first mentioned insulators, a second anode attached to said third insulator and enclosing the other 01' said first mentioned insulators.

5. A full wave rectifier comprising two spaced insulators, a cathode and cathode shield extending from one insulator to the other, a third insulator about the mid portion of said cathode and shield, an anode attached to said third insulator and enclosing one of said first mentioned insulators, a second anode attached to said third insulator and enclosing the other of said first mentioned insulators.

6. A full wave rectifier comprising two spaced insulators, a cathode and cathode shield extending from one insulator to the other, a third insulator about the mid rtion 01' said cathode and shield, an anode attached to said third insulator and enclosing one of said first mentioned insulators, a second anode attached to said third insulatorv and enclosing the other of said first mentioned insulators, said shield having one set of openings therein for one anode and another set oi! openings for the other anode.

7. A full wave rectifier comprising two spaced insulators, a cathode and cathode shield extending from one insulator to the other, a third insulator about the mid portion of said cathode and shield, an anode attached to said third insulator and enclosing one of said first mentioned insulators, a second anode attached to said third insulator and enclosing the other oi said first mentioned insulators, sa d shield having one set of openings therein for one anode and another set of openings for the other anode and a partition extending from said shield towards said cathode and having one set oi said openings on one side and the other set of openings on the other side thereof.

8. A full wave rectifier comprising an elongated cathode, two anodes surrounding adjacent 10ngitudinal lengths of said cathode and coaxial therewith and an insulator structure supporting the adjacent edges of said anodes, said insulator structure being annular and coaxial with said cathode and anodes and surrounding a portion oi said cathode and also having an annular groove in its periphery, the adjacent edges of said anodes overlying the outermost periphery of the insulator structure and partly extending into said groove.

9. A full wave rectifier comprising two spaced insulators, a cathode extending from one insulator to the other insulator, a third insulator about the mid portion 01 said cathode, two anodes each enclosing an end 01 said cathode, each of said anodes being in contact with said third infilator and one 01' said first mentioned insula 10. A discharge device comprising a lower insulator, an upper insulator, a perforated cylindrical shield supported on said lower insulator and supporting said upper insulator herefrom, a heater wire extending from an opening in said lower insulator towards said upper insulator, a coated cathode sleeve surrounding said heater wire and resting on said lower insulator, means connecting the upper portion of said coated cathode sleeve and the upper portion of said heater wire together and anode means adjacent said coated cathode sleeve.

11. A discharge device comprising a lower insulator, an upper insulator, a perforated cylindrical shield supported on said lower insulator and supporting said upper insulator therefrom, a heater wire extending from an opening in said lower insulator towards said upper insulator, a coated cathode sleeve surrounding said heater wire and resting on said lower insulator, means connecting the upper portion of said coated cathode sleeve and the upper portion of said heater wire together, the lower end of said heater wire extending through said lower insulator and a flexible connection attached thereto permitting elongation of said heater wire.

12. A discharge device comprising a lower insulator, an upper insulator, a perforated cylindrical shield supported on said lower insulator and supporting said upper insulator therefrom, a heater wire extending from anopening in said lower insulator towards said upper insulator, a coated cathode sleeve surrounding said heater wire and resting on said lower insulator, means connecting the upper portion of said coated cathode sleeve and the upper portion of said heater wire together, the lower end of said heater wire extending through-said lower insulator and a flexible connection attached thereto permitting elongation of said heater wire, said flexible connection comprising a metal ribbon having aflat portion secured to the heater wireand'another fiat portion bent at an angle thereto and anchored on the bottom of said insulator.

13. A discharge device comprising a lower insulator, an upper insulator, a perforated cylindrical shield supported on said lower insulator and supporting said upper insulator therefrom, a heater wire extending from an opening in said lower insulator towards said upper insulator, a coated cathode sleeve surrounding said heater wire and resting on said lower insulator, means connecting the upper portion of said coated cathode sleeve and the upper portion of said heater wire together, the lower end of said heater wire extending through said lower insulator and a flexible connection attached thereto permitting elongation of said heater wire, said flexible connection comprising a flat portion anchored to the underside of said lower insulator and two spring members extending from said flat portion to opposite sides of the lower end of said heater wire and secured thereto.

14. A flexible connection to a heater-wire extending through an insulator of a discharge device comprising a flat portion anchored to the surface of said insulator and two spring members extending from said flat portion to opposite sides of the heater wire and secured thereto.

15. A discharge device comprising a lower insulator, an upper insulator, a perforated cylindrical shield supported on said lower insulatoriand supporting said upper insulator therefrom, a heater wire extending from an opening in said lower ink sulator towards; said upper insulator, a coated cathode sleeve surrounding said heater wire and-v resting on said lower insulator, means connecting the upper portion of said coated cathode sleeve and the upper portion of said heater wire together, said last mentioned means having ears excathode sleeve surrounding said heater wire andresting on said lowerin'sulator, means connecting the upper portion of said coated cathode sleeve and-the upper portion of said heater wire togetl'ier,- a third insulator surrounding the mid portion of said cylindrical shield and two anodes, each-anode connected respectively to the upper or lower insulator and extending to the third insulator. j

17. A discharge device comprising a lower insulator, 'an upper insulator, a perforated cylindrical shield-supported on said lower insulator and supporting said upper insulator therefrom, a heaterwire extending from anopening in said lower insulator towards said upper insulator, a coated cathode sleeve surrounding said heaterwire andresting on said lower insulator, means connecting the upper portion of said coated cathode sleeve and the upper portion of said heater-wire together, a third insulator surrounding the mid portion of said cylindrical shield and having a peripheral groove therein and two anodes,each anode connected respectively to the upper or lower insulator and extending to the groove in said third insulator.

18. A discharge device comprising a cathode, a--

perforated cylindrical sleeve enclosing said cath-'-' ode, an insulator surrounding the mid portion of said cylindrical sleeve, anode means supported on said insulator and means supporting'said'insulator on said sleeve comprising metal brackets attached to the outer cylindrical surface of said sleeve and confining saidinsulator therebetweem:

WARD W. WATROUS, ,JR. 

